Field of the Invention
The present invention relates to a method and apparatus for generating a digital last for the manufacture of a shoe, in particular of a sports shoe.
Background
A last for a shoe is typically a mechanical form that has a shape adapted to form a shoe around it and which, when removed from the shoe, leaves a cavity for the reception of a human foot. Shoemakers use lasts for the manufacture of shoes. As such, it has been known for a long time to use lasts specifically made for a person's foot to manufacture a shoe.
However, nowadays shoes are typically mass products which do not take into account specific properties of a person's foot, mainly due to complexity and costs. Rather, lasts are usually provided based on average foot sizes and shapes. For instance, a shoe having a specific size (for instance, a running shoe having men's size 10) is manufactured using a last having a shape corresponding to average men's feet having the specific size of the shoe.
It is apparent that any deviation of a person's foot from the average foot shape (such as broader or narrower shape of the foot) cannot easily be taken into account for a mass product due to increased complexity and costs of the production of the shoes. Also, different persons may have different preferences regarding the fit of shoes which may not be reflected by a standard shoe that has been manufactured based on average values.
Consequently, one trend in manufacturing aims at producing articles which are adapted to the person's needs. With respect to shoes, several approaches are known in the prior art.
For instance, the US patent application publication US 2010/0229422 A1 discloses a customized shoe and insole, in particular a method and apparatus for determining the shape of a foot and for making a shoe or insole. In this publication, it is disclosed that a foot shape can be captured by scanning with an optical or mechanical probe or scanner. The determined shape can then be slapped-on to the bottom of a 3D representation of an existing last.
The Chinese patent application publication CN 101711614 A discloses a customized insole image sensing system and method. To this end, tested foot shape and shoe shape information are converted into customized insole manufacturing information. The Japanese patent application publication JP 2005-169015 A also discloses the measurement of foot dimensions for selecting an appropriately sized shoe.
The international patent application publication WO 2007/021865 A discusses a custom fit system with an adjustable last. After the length size is calculated, the appropriately sized shoe and last are assembled together and subject to infrared radiation until a heat malleable material becomes plastic. Adjustments are then made to the last in accordance with adjustment factors to provide custom width sizing.
However, none of the approaches known from the prior art allow for a cost efficient manufacture of lasts and shoes by taking into account the specific properties of a person's feet, so as to provide a well-fitting, easily manufactured shoe.
It is therefore the technical problem underlying the present invention to provide a method and apparatus for a cost efficient manufacture of shoes by taking into account the specific properties of a person's feet, so as to provide a well-fitting, easily manufactured shoe, thereby overcoming the disadvantages of the prior art at least in part.